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470, 470CW,
471, 471CW, 473, 473CW
Ring
Height:
1.975
The ring height is measured from the top of the cover down to the pressure plate
when the unit is bolted together. On
the top of the cover near one of the spring guides is a 3/16 inch hole with the
ring height measurement marked next to it.
To measure the ring height, insert the narrow end of a dial caliper
through the hole and down flat to the pressure ring.
This number is the ring height measurement.
When the ring height moves to 1.985, a .010 wear shim will need to be
removed from the flywheel studs between the pressure plate and cover.
After reassembling the unit to the flywheel, the ring height should be
rechecked and back at 1.975.
Initially
setting up the clutch
Install the
studs (492) in the flywheel using the 11-inch long style bolt circle.
Use loctite 271 (red) when installing.
Place one -
.050 shim and 2 or 3 - .010 shims (550 shim set) on each stud.
Bolt the pressure plate down to the flywheel with the disc in place and
measure the ring height. Add or
remove shims as necessary to achieve the ring height listed above.
ADDING SHIMS WILL INCREASE THE RING HEIGHT; REMOVING WILL DECREASE.
Be certain to use the same number of shims on each stud!
Static
Pressure: (written
on the side of the red cover)
470, 470CW
360 lbs. (adjust counterclockwise 15 lbs./turn max. seven
turns. (Range: 360-990 lbs.)
471, 471CW
800 lbs. (adjust counterclockwise 20 lbs./turn max. seven
turns. (Range: 800-1640 lbs.)
473, 473CW
1200 lbs. (adjust counterclockwise 20 lbs./turn max. seven
turns. (Range: 1200-2040 lbs.)
NOTE:
Turn the adjuster out until you start to feel tension on the screw and
begin your turn count from this point.
To return to the original base pressure, turn the screws in until you
feel the pressure relieved from the screw.
DO NOT GO BEYOND THIS POINT AS YOU MAY LOCK THE ADJUSTER SCREW INTO THE
ADJUSTER! Be sure to keep a record
of what your clutch is set at for future changes.
Counterweight Adjustment Weights
Counterweights should be installed with the bolt heads in the direction of
rotation. RAM offers a gram weight
scale under part number 578 and complete counterweight kits part number 570.
Steel Bolt 1/4
x 3/4
7.6g
Aluminum Bolt 1/4
x 3/4
2.2g
Steel Nut
(large)
3.3g
Steel Nut
(thin)
2.2g
Aluminum Nut
1.1g
Air Gap:
.065 Increase/decrease as necessary.
Note: Proper adjustment on the
two-step activation switch on the clutch pedal is critical to achieving proper
clutch performance. Ideally, the
two-step should turn off just before the clutch engages.
Check this at home before going to the track with a test light on the
switch!
Optimum
performance with single disc iron clutches is achieved by leaving at lower
RPM’s than you may be accustomed to. This
allows the clutch to slip some on launch, and drive the engine RPM back up into
the power band. Additionally,
leaving higher brings the counterweight effect of the clutch in much stronger
and may cause the clutch to appear too aggressive on launch.
Try it lower and you will be pleasantly surprised.
Data recording computers:
The most
effective tuning tool in your trailer is a data-recording computer.
By reading engine, driveshaft, and clutch RPM, you can determine exactly
what the clutch is doing off the starting line and through the gears and make
educated decisions on how to change your clutch settings.
This information also allows us to offer accurate technical assistance.
Maintenance:
To achieve
optimum performance it is best to service the unit periodically.
Iron clutches will tend to build a glaze over time that makes the clutch
more aggressive. How much you slip
the clutch will determine the length of time between maintenance.
In general, you should service the clutch between every 10-30 runs.
Clutch
disc:
The best
method for deglazing the disc is to use a disc-cutting machine.
If unavailable, use a sanding block to remove the glazed material and
floater plate glaze with a coarse 40-grit paper.
Work carefully around the disc to maintain its flat surface.
Avoid power sanding equipment as is tends to make the disc surface uneven
and tapered. Use a new piece of
paper for each disc side; the disc is very coarse and wears the sandpaper down
quickly. RAM RECOMMENDS A MAXIMUM
OF 60-80 RUNS ON IRON DISCS.
Pressure
Plate/Flywheel:
Again using
coarse sandpaper, remove any discoloration from both of these surfaces.
After servicing the clutch reassemble the unit measure the ring height.
Remove the wear shims as necessary to set the height back to 1.975”.
At this point your lever height and spring pressure will be reset to
their original positions.
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